Material spreader system with hydraulic drive and speed control means

ABSTRACT

This invention relates to material spreaders of the type including: a hopper, a prime mover for propelling the hopper at predetermined speeds, a movable unloading assembly for spreading the material from the hopper on the ground at a rate dependent upon the nature of the material and the ground speed of the hopper, a hydraulic motor for driving the unloading assembly, a hydraulic pump, and a control unit between the hydraulic pump and the hydraulic motor for varying the speed of the motor. The control unit employs a fluid-flow proportioning device connected in parallel-circuit relationship with an operable 3-way valve to provide at least two speeds for the motor.

United States Patent [1 1 Riley Dec.4, 1973 MATERIAL SPREADER SYSTEMWITH HYDRAULIC DRIVE AND SPEED CONTROL MEANS [76] Inventor: John R.Riley, 7139 Sharpcrest,

Houston, Tex. 77036 [22] Filed: Aug. 7, 1972 [21] Appl. No.: 278,680

Primary ExaminerRobert B. Reeves Assistant Examiner-Thomas E. KocovskyAttorney-Michael P. Breston et a].

[57] ABSTRACT This invention relates to material spreaders of the typeincluding: a hopper, a prime mover for propelling the hopper atpredetermined speeds, a movable unloading assembly for spreading thematerial from the hopper on the ground at a rate dependent upon thenature of the material and the ground speed of the hopper, a hydraulicmotor for driving the unloading assembly, a hydraulic pump, and acontrol unit between the hydraulic pump and the hydraulic motor forvarying the speed of the motor. The control unit employs a fluidflowproportioning device connected in parallel-circuit relationship with anoperable 3-way valve to provide at least two speeds for the motor.

4 Claims, 2 Drawing Figures MATERIAL SPREADER SYSTEM WITH HYDRAULICDRIVE AND SPEED CONTROL MEANS BACKGROUND OF THE INVENTION Various typesof material spreaders are known and used. Such spreaders typicallyinclude: a hopper mounted on a truck chassis aconveyer positioned toreceive the material from the hopper, and means for moving the conveyerat a linear speed which is proportional to the ground speed of thetruck. The ground speed depends on the selected gear and, for truckswith two-speed axles, on the selected axle ratio. When maintaining thesame gear, say second gear, the forward speed of the truck is varied bychanging from one axle ratio to the other, which can be easilyaccomplished by manipulating an axle ratio control element.

It is desired that the conveyers drive automatically correlate the speedof the conveyer with the speed of the truck so as to spread the materialon the ground at a constant rate.

It is particularly desired for this correlation to be automatic, so thatno human intervention is required to change the speed of the conveyer inreponse to a change in the axle ratio.

SUMMARY OF THE INVENTION The above and other apparent objects areaccomplished in a preferred embodiment of this invention by employing,in the hydraulically-powered drive of the conveyer, a 3-way valve inseries circuit between the pump and the motor, and afiuid-flow-proportioning device in parallel with the 3-way valve. The3-way valve is operable by means which are tied to the control meansused to change the axle ratio. In this manner, whenever the axle ratiois changed, the 3-way valve will also be automatically operated. The3-way valve can either by-pass the proportioning-device or it canallowit to function as afluid divider, W

The hydraulic motor will have a greater speed when the proportioningdevice is by-passed, and a reduced speed when the proportioning deviceis not by-passed.

In a similar manner, there can be beneficially employed anotherfluid-flow-proportioning device also connected in parallel with another3-way valve. Such an additional combination will add two additionalspeeds for the hydraulic motor. In sum, for each fluidproportioningdevice, two additional speeds are obtained for the hydraulic motordriving the conveyer.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic representationof a material spreader of this invention which automatically correlatesthe speed of the material unloading assembly with the axle ratioselector, and

FIG. 2 is a hydraulic circuit-diagram of the hydraulic control unit usedin FIG. 1.

DESCRIPTION OF THE SPREADER In FIG. 1, a self-propelled spreader vehicleis shown movable over the earths surface 12. On the chassis of vehicle10 is provided a hopper 14 for storing therein a material for example,limestone or fertilizer. The unloading of the material from hopper 14 isaccomplished by a movable assembly which is powered by a hydraulic motor15.

In the preferred embodiment, the material-unloading assembly includes aconveyer assembly 16. It is powered by a hydraulic power generatorsystem including a hydraulic pump 17 for feeding the hydraulic motor 15.Pump 17 receives at its inlet 18 a low-pressure fluid on line 19 anddischarges its high-pressure fluid to its outlet 20 on high-pressureline 21. Both pump 17 and motor 15 are, preferably, of theconstant-displacement type, wherein the volume of fluid displaced byeach is proportional to the RPMs of their respective shafts.

Motor 15 has an inlet 22 and an outlet 23. The volume of fluid flowinginto inlet 22 will be automatically controlled by afluid-flow-controller, generally designated as 24, having a fluid inlet25 and two fluid outlets 26 and 27. Generally, the hydraulic circuit isas follows: outlet 26 is coupled to inlet 22 via a fluid line 28; outlet27 is coupled to inlet 29 of a fluid reservoir 30 via a line 32 andoutlet 23 is coupled to inlet 27 via a fluid line 31.

Shaft 35 of motor 15 is coupled through a coupling device 36 to theconveyers power train, generally designated as 37 and of conventionalconstruction. In such conveyers there is a mobable member, typically achain 38 which is movable in a linear direction as indicated by thearrow 39. The power train 37 has means (not shown) to change the speedof chain 38 to correspond with the selected gear in the gear box 40 ofvehicle 10.

The material from hopper 14 is unloaded onto the movable chain 38through an adjustable gate 41. From the chain, the material drops onto afan spinner, generally designated as 42, of conventional construction.Unit 42 includes a gear box 43 driven by a drive shaft 44 which iscoupled by suitable means (not shown).

Vehicle 10 includes a prime mover or engine 45 coupled to gear box40'whose gear selector handle 46 allows for the selection of the desiredgear. It is conventional for such gear boxes to provide a power take-off47 having a shaft 48 whose RPM is determined by the selected gear in box40. Shaft 40 is mechanically coupled to the input shaft 49 of thehydraulic pump 17 by a drive shaft 50 which is provided at its ends withuniversal joints 51 and 52, respectively.

The propulsion of vehicle 10 is accomplished by connecting the gear box40 with the rear axle drive unit, generally designated as 53, through adrive shaft 54 having at its ends universal joints 55, 56, respectively.It is also conventional on such vehicles for the axle drive unit 53 tohave two distinct axle ratios, typically 6:8 and 7:9. The selection of aparticular axle ratio is accomplished by a shifting means 57 which couldbe vacuum operated, mechanically controlled, etc. In the preferredembodiment shifting means 57 is electrically operated through a line 58leading from a terminal 61 of a manually-operated switch 62 whose otherterminal is connected via line 63 to the battery 64. Switch 62 willestablish galvanic continuity between the battery 64 and line 58 onlywhen gear box 40 is in gear. Switch 62 is conveniently positioned nearthe gear-shift selector 46.

GENERAL DESCRIPTION OF CONTROL UNIT 24 Referring now more specificallyto FIG. 2, wherein the same numerals are used to designate the sameparts, it is desired, as previously mentioned, for simplicthe RPM of itsshaft 49, and the RPM of shaft 35 shall be proportional to the rate offluid flowing through the motors inlet 22. Accordingly, it is the mainfunction of control unit 24 to selectively change the ratio between thevolume V, flowing out of pump 17 and the volume V,,, flowing into motor15. The control unit 24 will allow for ratio V /V to have predetermined,discrete values depending upon the nature of the material in hopper 14and the particular axle ratio selected by selector 57.

DETAILED DESCRIPTION OF CONTROL UNIT 24 One ratio for V /V, is achievedby providing a 3-way valve 70 which may be a manually-operated valvehaving an inlet 71 and two outlets 72, 73. Connected in parallel-circuitrelationship with valve 70 is a fluid-flow-proportioning device having aproportionality constant X, generally designated as 74, whose inlet 75is connected to the outlet 73, and one of its outlets 76 is connected tooutlet 72 through a line 77 and a check valve 78. Its other outlet 79 isconnected to the return, low-pressure line 31 through a line 80.

To obtain another ratio for V /V there is provided another 3-way valve81 having an inlet 82 and two outlets 83 and 84. Connected in parallelwith valve 81 is another fluid-flow-proportioning device 85, having aproportionality constant Y, whose inlet 86 is connected to outlet 84,and one of its outlets 87 is connected to outlet 83 through a line 88and a check valve 89. Its other outlet 90 is connected to the returnline 80.

To couple and de-couple the fluid-flowporportioning devices 74 and 85,there is provided a suitable pilot valve 91 which is, preferbly,electrically operated. Other modes of operation for valve 91 could beused. Valve 91 can be a solenoid valve operated through a line 92connected to the battery 64 through a switch 93 (FIG. 1). The inlet 94of valve 91 is connected to outlet 72. The outlets 95, 96 of valve 91are connected to the return line 80 and to inlet 82, respectively.

Since the proportioning or fluid-divider device 74 is used dependentupon the material used in hopper 14, which is not frequently changed,valve 70 may be manually operated by a handle 70'. Conversely, sincefluid divider 85 is used dependent upon the particular axle ratioselected by selector 57, which may change many times in a relativelyshort time span, it is convenient for valve 81 to be electricallyoperated. It can be a solenoid valve controlled by a line 97 alsoconnected to terminal 61. Accordingly, line 97 will be electricallyenergized whenever line 58 is energized by switch 62. In other words,the manipulation of switch 62 will select the desired axle ratio. Suchselection will also automatically determine the flow condition in the3-way valve 81 and, hence, the value of ratio V,,,/V,,.

The fluid-flow-proportioning devices 74 and 85 are commerciallyavailable and may be purchased, for example, from the GresenManufacturing Company. They come in various proportioning ratios,including X and Y. They are pressure compensated as represented by thearrow 98. The arrow 99 designates that the fluid flowing into, say inlet75, is divided in accordance with the fixed ratio X between its outlets76 and 79. The dividers 74 and 85 are similar in their internalconstruction, as is well known to those skilled in the art. Thisinvention is therefore not limited to any particular type offluid-flow-proportioning device, and while it is preferred to employsuch devices having fixed ratios, similar devices with adjustable ratioscould equally be employed, if higher cost and greater complexity are nottoo objectionable.

OPERATION OF THE SPREADER In operation, hopper 14 will be loaded with asuitable material, such as limestone, fertilizer, etc.

Lime Operation, V,,,/V,, l

Assume that hopper 14 is loaded with lime and that it is desired thatthe ratio V /V, l for the high axle ratio. Vehicle 10 will be propelledforward on ground 12 typically by moving gear shift handle 46 intosecond gear. The manipulation of switch 62 will actuate selector 57 togive the desired axle ratio, in a conventional, well-known manner. Ifthe driver selects the high axle ratio, thereby causing vehicle 10 tomove at a relatively-faster, ground speed, it will be necessary forchain 38 of conveyer 16 to also move at a corresponding relatively-high,linear velocity. In this manner, the lime may be spread by spreader 42at a faster rate.

After the driver loads hopper 14 with lime he will I move handle ofvalve 70 to its lime position which will allow fulid to flow directlybetween inlet 71 and outlet 72, thereby by-passing divider 74. If pilotvalve 91 is not energized, then 72, 94 and 95 will be in fluidcommunication, and no fluid will reach outlet 96. If pilot valve 91 isenergized by switch 93, there will be established direct fluidcommunication between inlet 94 and outlet 96, as shown in FIG. 2.

When the high-axle ratio is selected, line 97 is denergized and directfluid communication is established between inlet 82 and outlet 83.Accordingly, since no fluid is bled off by any of the valves 70, 91 and81, V,, V, and hence V,,,/V,, =1.

Lime Operation, V,,,/V,, Y

When the low axle ratio is selected, line 97 is energized, and fluidflowing into inlet 82 flows out through outlet 84 into the proportioningdevice which feeds back to outlet 83 a portion YV,,, and the remainderportion flows out through outlet 90, return line 80, return line 31, andback into reservoir 30. Hence, V /V, is equal to the ratio Y establishedby the fluid-flowproportioning device 85, hence V /V, Y.

It will be appreciated that the shifting between V,,,/V,, l and V /V, Yis automatically accomplished without human intervention.

It will also be noted that when it is desired for the ratio V,,,/V,, 0,that is, for the conveyers drive train 37 to be de-energized, all thatis necessary is to deenergize line 92 of pilot valve 91 and the entirefluid V, will flow from inlet 94 to outlet and back to return line 80.As previously mentioned, in the lime mode of operation. thefluid-proportioning device 74 was rendered ineffective by valve 70.

Fertilizer Operation, V /V, X

In the fertilizer mode, the operator loads hopper 14 with fertilizer andmoves handle 70' to its fertilizer po- Fertilizer Operation, V /V XY Ifdevice v85 is not by-passed then V,, XYV,,. Again, device 85 will becomeeffective or ineffective in dependence upon the axle ratio selected byselector 57 through switch 62, and V /V, will correspondingly switchbetween the values X and XY.

In accordance with the above description, it is apparent that with twodividers the ratio V /V, can be made equal to 0, X, Y, XY, or 1, andthat the control unit 24 may include only one fiuid-flow-proportioningdevice 85, if it is contemplated to use spreader for lime only, or threeor more such devices, if it is contemplated to spread three or morematerials at three or more different spreading rates.

It will also be appreciated that the rotation of shaft 49 and, hence,the value of V is determined by the driving gear selected, typically thesecond gear. Should it be necessary or desirable to drive vehicle 10 inthe first or third gear, an internal adjustment in the power train 37 ofthe conveyer 16 will be required to compensate for the gear change in amanner which will be obvious to those skilled in the art.

It will therefore be obvious that many other modifications may be madein the apparatus particularly disclosed herein. The invention istherefore not to be considered limited to the preferred embodimentsshown in the drawings, but rather only by the scope of the appendedclaims.

What is claimed is:

1. A material spreader comprising:

a hopper mounted on a chasis,

at least one axle for supporting said chasis,

at least one pair of wheels rotatably mounted on said axle;

transmission means including an axle ratio selector for setting theratio of said axle thereby controlling the speed of hopper propulsionover the earths surface;

a movable unloading assembly positioned under said hopper for receivinga material from said hopper and for spreading it on the ground;

a hydraulic motor coupled to said unloading assembly for driving it at aspeed proportional to the speed of the motors shaft;

a hydraulic pump having a shaft mechanically coupled to saidtransmission means for feeding fluid to said motor from a reservoir;

said pump and said motor each being of the constant volume displacementtype wherein the volume of fluid displaced is proportional to theangular speed of rotation of the shaft;

a hydraulic control unit coupled between said pump and said motor, saidunit comprising: a first 3-Way valve in series circuit between said pumpand said motor;

a first fluid-flow proportioning device in parallel circuit with saidfirst valve, said valve being automatically and solely operable by saidaxle ratio selector thereby changing the ratio V /V between the volume Vdelivered by said pump and the volume V, received by said motor,independence upon the setting of said axle ratio selector whereby thespeed of the material unloading assembly is automatically correlatedwith the speed of said axle.

2. The spreader of claim 1 wherein said control unit further includes: asecond 3-way valve in series circuit with said firstQ-way valve; a

a second fluid proportioning device connected in parallel circuitrelationship with said first valve between said first and second valves;and

means for operating said second valve to thereby change from onepredetermined volumetric ratio to another predetermined ratio of fluiddelivered by said pump to said first valve.

3. The spreader of claim 1 wherein:

said axle ratio selector is electrically-operated, and

said first valve is electrically-operated simultaneously with theoperation of said axle ratio selector.

4. The spreader of claim 3 and further including:

a pilot valve coupled between said first and second valves, said pilotvalve being electrically-operated.

1. A material spreader comprising: a hopper mounted on a chasis, atleast one axle for supporting said chasis, at least one pair of wheelsrotatably mounted on said axle; transmission means including an axleratio selector for setting the ratio of said axle thereby controllingthe speed of hopper propulsion over the earth''s surface; a movableunloading assembly positioned under said hopper for receiving a materialfrom said hopper and for spreading it on the ground; a hydraulic motorcoupled to said unloading assembly for driving it at a speedproportional to the speed of the motor''s shaft; a hydraulic pump havinga shaft mechanically coupled to said transmission means for feedingfluid to said motor from a reservoir; said pump and said motor eachbeing of the constant volume displacement type wherein the volume offluid displaced is proportional to the angular speed of rotation of theshaft; a hydraulic control unit coupled between said pump and saidmotor, said unit comprising: a first 3-way valve in series circuitbetween said pump and said motor; a first fluid-flow proportioningdevice in parallel circuit with said first valve, said valve beingautomatically and solely operable by said axle ratio selector therebychanging the ratio Vm/Vp between the volume Vp delivered by said pumpand the volume Vm received by said motor, independence upon the settingof said axle ratio selector whereby the speed of the material-unloadingassembly is automatically correlated with the speed of said axle.
 2. Thespreader of claim 1 wherein said control unit further includes: a second3-way valve in series circuit with said first 3-way valve; a secondfluid proportioning device connected in parallel circuit relationshipwith said first valve between said first and second valves; and meansfor operating said second valve to thereby change from one predeterminedvolumetric ratio to another predetermined ratio of fluid delivered bysaid pump to said first valve.
 3. The spreader of claim 1 wherein: saidaxle ratio selector is electrically-operated, and said first valve iselectrically-operated simultaneously with the operation of said axleratio selector.
 4. The spreader of claim 3 and further including: apilot valve coupled between said first and second valves, said pilotvalve being electrically-operated.